#!usr/bin/env Python3

# -*-coding:utf-8-*-

__author__="William"

#define a class,just to learn to use class.

class Login(object):

    #those variable just use to be a flag.

    count = 3

    Flag = 1

    wrong_user_flag = 1

    wrong_user = ''

    #define a staticmethod function,just like a normal function to login

    @staticmethod

    def login():

        while Login.count > 0:

            if Login.wrong_user_flag == 0:

                username = Login.wrong_user

            else:

                username = input("Please input your username:>>>")

                Login.wrong_user = username

            password = input("Pleasw input your password:>>>")

            #call verify function

            Login.verify(username,password)

            Login.count -= 1

        else:

            if Login.Flag != 1:

                #add the wrong password user to black user list.

                with open("black_user.txt",'a') as fp:

                    fp.write("\n")

                    fp.write(username)

                    fp.write("\n")

    #define a staticmethod to verify the user info.

    @staticmethod

    def verify(user_name,password):

        #with to use to open a file.

        with open("black_user.txt", 'r') as fp:

            data = ''.join(fp.readlines()).split('\n')

        if user_name in data:

            print("Your are locked")

            Login.count = 0

        else:

            if user_name == "William" and password =="":

                print("Success,welcome to login")

                Login.Flag = 1

                Login.count = 0

            else:

                print("Wrong username or password")

                Login.Flag = 0

                Login.wrong_user_flag = 0

if __name__=='__main__':

    #To make a  instance.

    u1 = Login()

    #to call login

    u1.login()